Continuous-flow variable slit height thermal diffusion column



M. M. FINK.

Oct. 10, 1961 CONTINUOUS-4L0! VARIABLE SLIT HEIGHT THBRIAL DIFFUSIONCOLUMN Filed Sept. 12. 19%

6 a m m W 8 m 2m \l .l L a I I 2 k w I allay/ 2 .v v m.- ////n/ ll, 4 mu W 2 w FIG; I

FIG. 3

ELVH I. PINK "MW ATTORN E Y United States Patent A $003,639CONTINUOUS-FLOW? VARIABLE SLlI HEIGHT THERMAL DIFFUSION COLUMN Ms... M.Fink, Cleveland, Ohio, or, by theme is slgnments, to Universal OilProducts Company, Des

11]., a corporation of Delaware Filed Sept. 12, 1956, Ser. No. 609,464 3Claims; (Cl. 210-176) the temperature gradient, the degree of separationdesired, and the ratio of the rates of withdrawal of the products.

These variables whifli are interdependent, for the most part, are alsodependent upon the following additional variable factors in theapparatus used to carryout the PetentedQct. 10, 1961 FIGURE3isacrosssectiononlineHofFlG llookinginthedirectionofthemowsr Referringnow particularly to FIGURE L'the apparatusofthis inventionisconstmctedinthetollowingmanncr: An inner tubular'mcmber 26isIydisposedwithinanoutertubularmembermsoastoleave a \miform annularspace 11 as the separation chamber. Ibo annular space llbes a width notexceeding 0.15 inch and usually lea than 0.060 inch. I

The tubular member leis provided with a hollow jacket'12 adapted to aheat transfer fluid. The jacketlz is provided with openings 13 and 14through which the heattransfer medium may be introduced and withdrawnby'means'of the conduits 15 md The inner tubular member 26 has a hollowinterior 26a and a hollow extension-'27 commuuicatingtherewith at theopening 31. A heat transfer medium may be introduced and withdrawn fromthe hollow interior 26a of tubular member 26 by means ofthe conduit 29.which separation: the slit width, i.e. the distance between the hot andthe cold wall or the distance of the thermal diffusion section acrosswhich a temperature gradient is maintained; the surface of each slit,i.e., the sum of products of the length andthe outside and insidecircumferences of the and outer tubes, respectively. The effect thesevariables have upon one another are known to or can readily bedetermined by one skilled in the art. It has been found that there is adefinite optimum slit length for the thermal diflusion operation on agiven material at which maximum separation will be obtained, all otherfactors being constant. The optimum slit length vary depending upon theproperties of the material to be separated if all other variables, suchas slit width and temperature gradient For example, the separation of amixture of ethylene glycol and benzyl alcohol will require a differentslit length for optimum separation thanlthe. optimum which will berequired for the separation of a mixture of isopropyl benzene andhexadecane, again with all other variables constant.

'Ihe\oth er. tactors, such as slit width and the tempera tures otthehotand cold wall, are generally also selected so as to be optimum for thematerial to be thermally difiused. Once these are selected, however,there will be an optimum for the slit length; slit lengths less than theoptimum will not give as good a separation as the optimum length; slitlengths more than the optimum length will not give any better separationthan does the optimum length and will use more heat for no enhancedefiect. Accordingly, it is an object of my invention to provide athermal dilfusion apparatus in which the length of the slit can bevaried.

In brief, my invention is a tubular type thermal diffusion apparatuscomprising a pair of tubular members in which one of the tubes isadjustable with respect to the other in an axial direction so thateffective length of the separation chamber may be varied at will. Withthe apparatus of this invention, it is possible to make full advantageof the aforesaid optimum slit length.

The invention will be better understood by referring to the attachedpatent drarwing, wherein similar numerals denote similar partsthroughout and:

FIGURE 1 is a crossasectional view of the entire FIGUREZisatopviewoftheapparatuspartlyin section taken along line 2-2 of FIGURE 1 looking inthe directionofthe arrows;and

communicates with anopening 30 in the tubular member 26 and the hollowstem 27.

The tubular member 10 has a recessed port-groove 17 near the lowerextremity of the jacketed portion, which has a'pair of conduits 19 and20communicating therewith at opposite sides. The groove 17 forms areservoir leading to the thermal diffusion slit ll and the conduits 19and 20 maybe used to introduce or withdraw liquids fromthe separationchamba' 11. The tubular member 26 has a recessed groove 33 located nearits upper -extremity which serves as -'a reservoir for the. separationchamber 11 and'has a pair of conduits 35 and communicating therewith;Liquid may be introduced or withdrawn through the conduits 35 and 36.

The tubular member -10also has a'recessed groove 18 which is adapted toaate an O-ring gasket 21 which seals the annular space 11 at thebottomthereof. The tubular member 26 also has a groove 32 which is adapted toaccommodate an O-ri-ng gasket which sealstheannularspacellatmetopthereof. The tubular member 10 has a hollowextension 10 which extends below the thermal chamber 11. The hollowextensionlllahas nut-retainingmeans22-aflixedorsecuredtothebottomthereof which are adapted to accommodateflicknurledfnm ld. The bottom of hollow member 10aisakey24inan'opcning25.'

The tubular member 26 is positioned within the tubular member 10 so thatthe hollow extension 27 which is externally threaded passes through theopening 25 in the extension 10rof tubular member 10 and I the knurlednut 23. The threaded extension 27 has a keyway 28 in its face. A key 24in opening 25 engages the keyway 28 in extension 27 so as to prevent therotation of the tube 26 with respect to the tubular member 10 when thenut 23 is rotated.

The effective length of the separation chamber, i.e. the distance fromthe reservoir 33 to the reservoir 17, may be adjusted by turning the nut23 which will raise or lower the tubular member within the tubularmember 10. Since the slit 11 which serves as the thermal diijfusionseparation chamber is sealed by the O-rings 21 and 34 which are free torotate in their respective grooves 18 and 32, the adjustment of the slitlength can be accomplished while the apparatus is in use since thesepuation chamber 11 remains efiectively sealed at all times. Theconduits 26, 35 and 36 may be connected to flexible conduits toaccommodate this movement.

The O-ring gaskets which are to be employed in the 3 rials. Preferably,the Owing gaskets are made from material which will be unaffected by theliquid which is to be separated in the apparatus.

The apparatus described herein may be used to conduct a variety ofthermal diflusion flow patterns. 7 For example, a material may be fedsimultaneously to conduits 35 and 19 while the productsmay be withdrawnat conduitsliifiand 20. r I

Modifications of theembodi-H. nt of the invention described herein mayoccur to those skilled in the art, but desire this application forLetters Patent to cover all snchimodifications as would reasonably fallwithin the scope of the appended claims.

I claim:

1, A thermal diifusion apparatus comprising a stationary ioute'r tubularmember and an inner tubular member having a smaller outside diameterthan the inside diameter of said outer tubular member movably mounted inconcentric relation to said outer member, said outer tubular memberhaving a seal retaining means and a seal operatively associatedtherewith, said inner ubular memher having a seal retaining means and aseal operatively associated therewith .spac dspart from said retainimeans and seal associated with said outer member so as to provide a,thermal diffusion separation chamber in the ann lar space between saidouter and inner tubular members, inlet conduit means. for introducing aliquid to said separation chamber, two outlet conduit means for withdawing two liquid products simultaneously from said separation chamber,first port means communicating with one of saidoutlet conduit means andsaid separation chamber located at the upper extremity of said innertubular member, second port means communicating with the other of saidoutlet conduit means and said separation chamber located at the lowerextremity of said outer tubular member, means for impressing atemperature gradient upon said separation chamber and means for movingsaid inner movable-tubular member in an axial direction relative to saidstationary outer member whereby the effective length of said separationchamber may be altered.

2. A thermal diffusion apparatus comprising a stationary outer tubularmember and an inner tubular member having a smaller outside diameterthan the inside diameter of said outer tubular member movably mounted inconcentric relation to said outer member, said outer tubulaimemberhaving a seal retaining means and an O-ring seal operatively associatedtherewith, said inner tubular member having a seal retaining means andan .O-ring sealoperatively associated therewith spaced apart from saidretaining means and O-ring associated with said outer member so as toprovide a thermal difi'usion separation chamber in the annular spacebetween said outer and inner tubular members, inlet conduit means forintroducing a liquid to said separation chamber, two outlet conduitmeans for withdrawing two liquid products simultaneously from saidseparation chamber, first port means communicating with one of saidoutlet conduit means and said separation chamber located at the upperextremity of said inner tubular member, second port means communicatingwith the other of said outlet conduit means and said separation chamberlocated at the lower extremity of said outer tubular member, means forimpressing a temperature gradient upon said separation chamber, andmeans for moving said inner movable tubular member in an axial directionrelative to said stationary outer member whereby the effective length ofsaid separation chamber may be altered.

3. A thermal difiusion apparatus comprising a station- ,ary outertubular member and an inner tubular member having a smaller outsidediameter than the inside diameter of said outer tubular member movablymounted in concentric relation to said outer member, said outer tubularmember having a seal retaining means and a seal operatively associatedtherewith, said inner tubular member having a seal retaining means and aseal operatively associated therewith spaced apart from said retainingmeans and seal associated with said outer member so as to provide athermal difiusion separation chamber in the annular space between saidouter and inner tubular members, inlet conduit means ,for introducing aliquid to said separation chamber, two outlet conduit means forwithdrawing two liquid products simultaneously from said separationchamber, first port means communicating with one of said outlet conduitmeans and said separation chamber located at the upper extremity of saidinner tubular member, second port means communicating with the other ofsaid outlet conduit means and said separation chamber located at thelower extremity of said outer tubular member, means for impressing atemperature gradient upon said separation chamber and means for movingsaid inner movable tubular member in an axial direction relative to saidstationary outer member comprising a screw-threaded member attached tosaid inner tubular member operably engaged to a nut secured bynut-retaining means attached to said outer tubular member whereby theefiective length of said separation cham ber may be altered.

References Cited in the file of this patent UNITED STATES PATENTS

